I'm working up to buying a Z2 and installing in '07 Sonata. I'm planning my wiring and install and I need some advice:

What's the consensus on where to put the GPS antenna--inside on rear deck or outside on rear roof or trunk roof. The inside is hugely simpler than outside but I'm worried about reception thru the glass as well as the blocking of a large portion of antenna's "view" by the roof.

I have tried both and by far the superior reception is outside. Sorry, that's just how it is. Inside you will reduce signal strength but for your application does it reduce it enough to hurt the navigation?

But I also have mine permanently install inside UNDER my dash.

The antenna needs a metal plate to stick to, not only will it keep it in place but the metal is a ground plane and increases it's ability to pick up sat signals. So if you put it inside the car, make sure you get a good metal plate, I got a 1/16 inch thick steel 3x3 plate and mounted it inside the car and stuck it to the antenna.

I tried on the roof: excellent reception all sats all the time.

I tried inside with just the metal foil they give you: too poor of a signal strength for accurate navigation.

Then I tried putting a thick metal plate below it while inside: and got about 75% of the signal strength. Decent enough for good navigation along with the vss wire.

So I kept it inside with the good piece of metal.

But of course try it where ever you want and see how it works. Check the signal strength and see how good it is in different positions. You can even roll down the window and stick it to the roof for a sec and see how it is up there. Your vehicle might work different than my Aviator and the best thing is to just try different locations and see what works for your vehicle.

Underneath the dash on the fender for mine. Works fine with no real problems with reception.

thats where my antenna is too.

Mine is on top of my dash near the corner of the windshield and I get very accurate reception.

Mine is on top of my dash near the corner of the windshield and I get very accurate reception.

That's where mine used to be, but I moved it under the dash. Slightly less accurate reception (but no ugly antenna on my dash )

yup. gotta keep the oem look.

I have mine behind the rear view mirror. Works great. All sats all the time.

Clean install and very easy to wire.

I put mine right under the plastic dash cover, right where the OEM GPS antenna goes.

I have mine mounted under the dash on top of the vent and have had no problems. My Z1 shows I have perfect reception too. Last thing I needed was another antenna mounted outside the truck in view like the sirius antenna.

Ya, no kidding. I tried EVERYTHING to get that sirius antenna to work without needing to put in on the roof. But in the end, I had to. At least it was a clean install, running the wire around the window edge molding and in through the door jam.

So let me get this straight. It is possible to place the GPS and the XM antenni under the dash and get a strong enough signal to work? My problem is that I did have a Z1 when it first came out and a couple of months later it was stolen. Since then I have moved and the new Z2 has come out which I should be getting within the month. Previously the antenni were placed on each side of the dash, but I thought it brought too much attention to the gear inside, so really never truly liked that placement. I was thinking of running both antenni to the roof and having it out of sight, but erked at the trouble of running the wires to the roof. But now you guys are saying that it can be mounted under the dash...? That would be great. DB did you tach or weld the metal plate? Can you place both antenni on the same plate? Man, this just opened a whole new thought process.

Thanks, you are guys are the greatest.

My GPS antenna is mounted inside of my dash near the windshield and it works fine. Can't see it.

yeah gps antenna wil work fine, but XM and sirius antennas should go outside.

I struggled with the same question/issue.

I ended up mounting the GPS antenna on top of dash, as far forward towards the windshield as possible. The dash has vent slots in it which gave me a natural access to inside dash where Z1 unit is. Placed metal plate under dash and under GPS antenna as ground plane for antenna. 1 to 2 bars signal strength - all Sats. You probably don't need the ground plane anyway, and it's separated by the thickness of the dash wall so probably doesn't even help so I wouldn't worry about it.

XM antenna was rounted to outside, just above windshield on roof on drivers side. Excellent signal strength - even sitting in my garage (and my house has a metal roof!). I found the GPS antenna coax a lot bigger in diameter than the XM coax and just didn't feel comfortable trying to route it outside.

I was thinking about mounting my antenna in my engine compartment.

Anyone have suggestions where I could mount it where it's NOT visible

and has excellent reception in an Avalanche?

Not a good place.

Any metal between an antenna and the sky will shield it from radio signals and render it ineffective.

Your nav system antenna could be mounted under your dash as long as you put it right up next to the roof of your dash and ensure it has a non--metallic unabstructed view of the sky (i.e. mount as far forward towards you windshield as possible and ensure no metal is covering it.

Also, you will add some gain to your antenna by mounting it on a metallic surface that's grounded (such as the top of your Z1 unit as long as there is no metal between the top of your antenna and windshield).

It won't hurt to try. If it doesn't work, you could put it on the dash as I did. It doesn't look too bad either.

Good luck.

I was thinking about mounting my antenna in my engine compartment.

 

Anyone have suggestions where I could mount it where it's NOT visible

 

and has excellent reception in an Avalanche?

I would put it in the factory location which is under the upper dash attached to the metal brace. That's where I put mine and the reception is excellent. I put mine on a small sheetmetal plate since I was missing the one that comes with it.

I was thinking about mounting my antenna in my engine compartment.

 

Anyone have suggestions where I could mount it where it's NOT visible

 

and has excellent reception in an Avalanche?

 

I would put it in the factory location which is under the upper dash attached to the metal brace. That's where I put mine and the reception is excellent. I put mine on a small sheetmetal plate since I was missing the one that comes with it.

Do you have a pic?

No, but I do have a diagram from the service manual.

Since I don't have the factory metal plate with the screw hole, I just used double-sided tape to attach it to the top of the metal bars in the dash (the gray 3M kind used to hold body trim on). I think I may have attached it to the driver side metal bar rather than the passenger side one like the factory setup, but I don't think it makes any difference which side of the dash you put it on.